Alkylene-bis-ureas



Patented Oct. 22, 1946 ALKYLENE-BIS -UREAS William Robert Boon, Blackley, Manchester, England, assignor to Imperial Chemical Industries Limited, a corporation of Great Britain N Drawing. Application April 4, 1944, Serial No. 529,525

6 Claims.

This application is a continuation-in-part of my copending applications Serial Nos. 425,006, filed December 30, 1941, and 505,037, filed October 5, 1943.

The present invention relates to new substituted ureas which are alkylene bis-ureas, and in particular are compounds of the general formula wherein X stands for the secondary amino group corresponding with an aliphatic or heterocyclic secondary amine XH as more fully described below; wherein R and R stand for alkyl groups, which are not necessarily alike, but which are such that they jointly contain not more than 8 carbon atoms; and wherein n is any integer from 2 to 6 inclusive.

Amongst the properties of these new alkylene bis-ureas which make them useful are their physiological properties, as shown by their effect on the living organism, which are such that they may be used as stimulants of the respiratory and vasomotor centres, and for that purpose they are very valuable, as the ratio of active dose to toxic dose is very low.

According to the invention the said new a1- kylene bis-ureas are made either by causing to react together one molecular proportion of a dialkylalkylenediamine, RNH(CH2) nNH-R' (where R, R and n have the significance given above) with two molecular proportions of a carbamyl chloride XCO-Cl (where X has the significance given above), or by treating a dialkylalkylenediamine (RNH-(CH2)1LNH- R' as before) with phosgene to give the corresponding bis-carbamyl chloride, and causing that to interact with two molecular proportions of an aliphatic or heterocyclic secondary amine of for mula XH as defined above.

In all the above cases, if the reaction is car-.

ried out in organic liquid medium and in the absence of extraneous acid absorbing agents, part of the amine (diamine or secondary amine, as the case may be) absorbs the liberated HCl and is thrown out of solution. Therefore, the molal proportionsabove indicated are the theoretical minima, and in actual practicean excess of the amine is preferably employed.

The secondary amine XH above referred to may be a member of the group consisti g of dialkyl amines, alkoxy-substituted dialkyl amines and heterocyclic compounds having an NHgroup in the ring. Typical representatives of this group are: dimethylamine, diethylamine, methyl ethylamine, di-n-propylamine, di-n-butylamine,

the special physiological properties above referred to, it is preferable to limit the molecular weight of the chosen secondary amine X--I-I as follows: to or less, if it is of a simple dialkylamine form or of a heterocyclic nature; to or less, if it i an alkyl-alkoxyalkylamine; and to 220 or less, if it is of the di(alkoxyalkyl) amine form.

As typical dialkyl-alkylene-diamines of formula RvNH-(CH2)n-NHR' above referred. to, the following may be mentioned: N::N'-dimethylethylene diamine, N:N'-diethylethylene diamine, N:N-dimethyltrimethylene diamine, N-methyl-N-ethylethylene diamine, N:N'-di-npropylethylene diamine, N :N' -di-n-buty1ethy1ene diamine, N zN'-dimethyltetramethylene diamine, N:N'-dimethylhexamethylene diamine, N ::N'-dimethyl-1 :2 -propylene diamine, N N -dimethyl- 1:3-butylene diamine.

The invention is illustrated but not limited by the following examples in which the parts are by weight.

Example 1 88 parts of diethylcanbamyl chloride dissolved in 120 parts of benzene are added with stirring to a solution of 53 parts of N:N'-dimethyltrimethylenediamine (obtainable from N:N-dimethyl-N N -diphenyl-trimethylenediamine by the method describedin respect of N :N- dimethylethylenediamine in Berichte der deutschen chemischen Gesellschaft 1918, vol. 51, p. 738) in 450 parts of benzene. When the reaction is complete the N :N-dimethyltrimethylenediamine dihydrochloride (which has M. P.

66 C.) is removed by filtration, and the filtrate I is shaken with 100 parts of saturated potassium carbonate, dried over anhydrous potassium carbonate and distilled whereby there is obtained 67 parts of N:N-dimethyltrimethylenediamine- N:N-dicarboxy1ic acid bis-diethylamide as a colourless liquid, B. P. 238 C. at 33 mm. pressure which is miscible in all proportions with water and the commoner organic solvents.

In a similar manner there are obtained the following:

(a) N :N-dimethylethylenediamine 7 N::N-dicarboxylic bis-piperidide (M. P. 90 0.).

(b) N-methyl-N-ethylethylenediamine-N N'-' dicarboxylic bis-dimethylamide (B. P. 205 0., at 22 mms. pressure).

(0) N N-diethylethylenediamine-N :N -dicar- 3 boxylic bis-morphclide (M. P. 98 C.), which is a colourless crystalline solid readily soluble in water, ethanol and benzene and sparingly soluble in light petroleum. The morpholine-N-carboxylic chloride used in making this substance has B. P. 13'7l38 C. at 33 mms. pressure and is obtained by the action of phosgene on morpholine in accordance with the method described in respect of diethylamine in Bulletin de la Socit chimique de Paris, 1904, 3rd series, vol. 31, p. 689.

(d) N:N-di-n-propylethylenediamine N:N- dicarboxylic bis-dimethylamide. (B. P. 208 C. at 18 mm. pressure). The N :N'-di-n-propylethylenediamine (B. i 189 c. dihydrochloride P. 300 C.) required is made by reacting di-p-toluene-sulphonylethylenediamine with n-propyl bromide by the method of Berichte, 1895, vol. 2.8., p. 3074, to give di-p-toluene-sulphonyl-di-n-pro= pylethylenediamine of M. P. 122 C. which is then hydrolysed by heating with 80% sulphuric acid at 150 C. for 5 hours.

(e N:N-di-n-butylethylenediamine-N:N'-dicarboXylic bis-morpholide (B. P. 229 C. at 0.4 mm. pressure, M. P. .l42 0.). The N:N-di-nbutylethylenecliamine required has B. P. 226 0., its dihydrochloride melts at 300 (3. with decomposition and its di-p-toluenesulphony1 derivative at 119 C. It is made in a manner analogous to that used for making N:N-di-n-propylethy1ene diamine.

(f) N:N dimethyltetramethylenediamine- N:N-dicarboxylic bis-diethylamide (B. P. 216 C. at mm. pressure). The N:N-dimethyltetramethylenediamine (B. P. 164 C., dihydrochloride M. P. 275 0.) required is made by con- (lensing lr-dibromobutane with scdium-p-toluenesulphonylmethylamide in Xylene at 1 i0 C. to give di-p-toluenesulphonyl-N N -dimethyltetramethylenediamine of M. P. 129 C. which is hydrolysed in the usual manner.

' (g) N:N dimethylhexamethylenediamine- N:N'-dicarboxylic bis-dimethylamide (B. P. 238 C. at 17 mm. pressure).

Example 2 21 parts of N:N-dirnethylethylenediamine carbonate is suspended in 250 parts of dry chloroform and the solution is saturated with phosgene at room, temperature. After it has stood for hours air is blown through the mixture to i remove the excess of phosgene. The mixture is then filtered to remove N:N'-dimethylethylenediamine dihydrochloride and from the filtrate the chloroform is distilled,'leaving a pale yellow, mobile somewhat lachrymatory liquid which is the bis-carbamyl chloride. This is dissolved in 100 parts of ether. parts of diethylamine are added. After the reaction is complete the whole is agitated with 150 parts of saturated aqueous sodium carbonate solution, the ethereal layer is separated and dried over anhydrous potassium carbonate. This dry ethereal solution is fractionally distilled to give as one fraction N:N- dimethylethylenediamideN:N -dicarboxylic bisdiethylamide as a colourless liquid, B. P. 339 C-. at atmospheric pressure or 224 C. at 13 mm. pressure which is miscible in all proportions with water and the commoner organic solvents.

Example 3 16 parts of N:N-dimethylethylenediamine dihydrochloride are dissolved in 150 parts of water, and sufficient 32% aqueous caustic soda is then added to make the solution alkaline to phenolphthalein and the Whole is cooled to 5 C.

25 parts of dimethylcarbamyl chloride are now added with stirring and cooling at such a rate that the temperature does not exceed 20 C., more caustic soda being added as required to keep the solution just alkaline to phenolphthalein. After stirring for 6 hours sufiicient solid potassium carbonate added to saturate the solution and the oil which separates out is dissolved up in parts of benzene. The benzene solution is dried over anhydrous potassium carbonate and the benzene is then distilled ofi. N:N-dimethylethylenediamine-N:N'-dicarboxylic bis-,dimethylamide (B. P. 193 C. at 20 mm. pressure) is thus obtained. It is a colourless oil which gradually solidifies to a crystalline mass; it is miscible in all proportions with water and the commoner organic solvents.

Example 4 20 parts of N:N-dimethyltrimethylenediamine are gradually added with stirring to a cooled solution of parts of phosgene in 500 parts of toluene, the temperature beingkept below -l0 C. After the addition is complete air is blown through the reaction mixture to remove the excess of pliosgene and the mixture is filtered to remove N N -dimethyltrimethylenediamine dihydrochloride. 3% parts ofpiperidine are added and after standing one hour the mixture is filtered to remove piperidine hydrochloride. The toluene is then distilled oiT hereby N :N-dimethyltrirnethylenediamine N:N dicarboxylic bis-piperidide is obtained. It is a colourless oil B. P. 205 C. at 0.75 mm. pressure which is readily soluble in ethanol and benzene and only slightly soluble in water.

In a similar manner there can be obtained N: N' -dimethyltrimethylenediamine N N -dicarboxylic bis(methyl-n-propylamide) and N :N'- dimethyltrimethylenediamine N:N' dicarboxylic bis-(ethyl-fl-ethoxyethylamide) Example 5 parts of N:N-dimethyltrimethylenediamine dissolved in 560 parts of toluene are added,

at l5 C., with stirring. to a solution of 280 parts of phosgene in MOO-parts of toluene. After the addition is complete, air is blown through the reaction mixture to remove the excess of phosgene; N N -dimethyltrimethylenediamine dihydrochloride separates out and is filtered oil and washed with dry toluene. The united filtrate and washings are then distilled whereby there is obtained N:N-dimethyltrimethylenediamine-N:N- dicarboxylic dichloride of B. P; 163-166 C. at 0.8 mm. pressure, together with some 1: 3 -dimethy1- 2-ketohexahydropyrimidine B. P. 14;0' C. at 44 mm. pressure.

To a solution of 11 parts of- N:N'-dimethyltrimethylenediamine-N N -dicarboxylic dichloride in 50 parts of benzene there is added a solution of 18 parts of methyl methoxyethylamine in; 50 parts of benzene, Methyl methoxyethylamine hydrochloride-separates out and is filtered off'and. the filtrate isdistilled whereby there is obtained N:N dimethyltrimethylenediamine N:N di-' carboxylic acidbis(methylmethoxyethylamide) of B. P. 253 0. at 16mm. pressure.

In a similar manner there are obtained:

(a) N:N-diethylethylenediamine-N':N'-dicarboxylic acidbis(ethyl methoxyethylamide) B. P. 239 C. at 17 mm. pressure.

'(b) N:N-di n} propylethylenediamine-N:N dicarboxylic acid bis(methyl ethoxyethylamide) of B; P. 255 C.- at 20 mm. pressure.

(c) N:N-dimethyltrimethylenediamine-N:N'- dicarboxylic acid bis(ethy1 ethoxyethylamide) of B. P. 253 (32/14 mm.

Example 6 17 parts of ethyl methoxyethyl-carbamyl chloride (made from ethyl methoxyethylamine and phosgene) dissolved in 50 parts of benzene are added with stirring to a solution of 14 parts of N:N-di-n-propyl ethylenediamine in 50 parts of benzene. N:N-di-n-propylethylenediamine dihydrochloride separates out and is filtered ofi. The filtrate is shaken with 50 parts of a saturated aqueous solution of potassium carbonate, dried over anhydrous potassium carbonate and distilled whereby there is obtained N:N-di-n-propylethylenediamine-N:N'-dicarboxylic bis(ethy1 meth oxyethylamide) of B. P. 265 C. at 25 mm. pressure.

Example 7 29 parts of di-(fi-ethoxyethyl) carbamyl chloride (of B. P. 165 C. at 19 mm. pressure) dissolved in 75 parts of toluene are added with stirring to 17 parts of N:N'-di-n-butylethylenediamine in 50 parts of toluene and the whole is refluxed gently for 6 hours. After cooling, the precipitated amine hydrochloride is removed by filtration, the filtrate refluxed for A2 hour with parts of water and distilled to dryness on the water bath under reduced pressure. The residue is extracted with hot 6080 petroleum ether and the extract fractionally distilled under reduced pressure whereby NzN'di-n-butylethylenediamine NzN dicarboxylic-bis-di(B-ethoxyethyl) amide distils over above 240 C. at 10 mm. pressure.

The di- (fi-ethoxyethyl) -carbamyl chloride used as starting material is made from phosgene and di-p thoxyethylamine, which itself is obtained by interaction of B-ethoxyethyl chloride with an excess of aqueous fi-ethoxyethylamine, or, less advantageously, by condensing aniline with ethylene chlorhydrin to give di-(B-hydroxy-ethyD- aniline, converting this to its sodium salt and reacting with diethyl sulphate to give di-(B-ethoxyethyD-aniline which is then converted into di-(e-ethoxyethyl) amine by the method described in respect of NzN-dimethylethylenediamine, in Berichte der deutschen Chemischen Gesellschaft, 1918, vol. 51, D. 7 38.

Whereas the above examples illustrate some embodiments of the invention, it will be obvious to one skilled in the art that many other embodiments and variations can be devised without departing from the spirit and scope thereof and it is therefore to be understood that the invention is not limited to the particular embodiments described above, but only as defined in the following claims.

In the claims below, the expression unsubstituted heterocyclic compounds shall be understood as referring to heterocyclic compounds whose hydrogen atoms have not been replaced by other atoms or radicals.

I claim:

1. Alky1ene bis-ureas having the structural formula:

XCO-NR(CH2) n--NR'-CO X wherein n is any integer from 2 to 6 inclusive, R. and R represent alkyl groups containing together not more than 8 carbon atoms and X represents the imino radical of a secondary amine being a member of the group consisting of dialkyl amines, alkoxy-substituted dialkyl amines, and unsubstituted heterocyclic compounds having an NH group in the ring.

2. Alkylene bis-urea having the structural formula:

X-CO-NR(CH2) n-NR'-CO-X wherein n is any integer from 2 to 6 inclusive, R and R represent alkyl groups containing together not more than 8 carbon atoms and X represents the imino radical of a dialkyl amine having a molecular weight not exceeding 120.

3. Alkylene bis-ureas having the structural formula:

X-CO--NR-(CH2) nNR'CO'-X wherein n is any integer from 2 to 6 inclusive, R and R represent alkyl groups containing together not more than 8 carbon atoms, and X represents the imino radical of an unsubstituted heterocyclic compound having an NH group in the ring and having a molecular Weight not exceeding 120.

4. N N -dimethyltrimethylenediamine-N N dicarboxylic-bis-diethylamide.

5. N:N-di-n-propyl-ethylene-diamine N:N'- dicarboxylic-bis-dimethylamide.

6, N:N'-di-n-butyl-ethylene-diamine-NzN -dicarboxylic-bis-morpholide.

WILLIAM ROBERT lBOON. 

